1. Field of the Invention
The present invention relates to a composite apparatus having a plurality of functions such as a printer function, a copy function and a facsimile function and a printer sharing method.
2. Related Background Art
The number of composite apparatuses is increasing nowadays. A composite apparatus has a plurality of functions including a digital copy function, a facsimile function and the like, and in addition a printer function for using the apparatus as a printer for an externally connected computer.
Most of composite apparatuses have the structure that a new function different from fundamental functions is added by mounting an option board for the new function on the composite apparatus.
A relation between a conventional composite apparatus and an option board with a printer function is illustrated in FIG. 3. The option board 2 having a printer function for the composite apparatus has a CPU bus which is a connection interface with a main controller 1 of the composite apparatus. The option board 2 is connected to the main controller 1 by the CPU bus via a relay IC 109 for data transfer therebetween. More specifically, page description language (PDL) data received from a computer 120 is analyzed by a printer controller 124 and developed in to a raster image which is input via a printer I/F 114 to the main controller 1 of the composite apparatus and stored in a RAM 122. CPU 108 checks whether a FAX job or a copy job is using a printer engine 4. If the printer engine 4 is being used, an operation stands by, whereas if the printer is not used, the raster image stored in RAM 122 is transferred via a printer I/F 118 to an engine controller 3 to print it out. If the printer engine is executing another job, the raster image may not be developed in RAM 122 but a busy is notified to the printer I/F 114 to make the development process stand by. In both cases, the printer board 2 cannot use a printer board for a general printer.
The conventional composite apparatus has the following problems. First, since the interface with the main controller is connected by the CPU bus, an already developed printer board for a general printer cannot be used. This is because the option board with the printer function and an already developed printer board for a general printer have different interface specifications and the already developed printer board has an interface capable of being directly connected to the printer engine.
Second, the printer board developed for a general printer exchanges various printer statuses to and from the printer engine, whereas the printer engine of a composite apparatus has far more statuses. Therefore, there is some mismatch between the status analyzed by the printer board and the status notified by the printer engine.
The printer board of a conventional composite apparatus is therefore required to determine an output destination of an output interface of a video signal and to modify a status notice from a connection interface with the main controller. Although both the option board and a general printer board have similar functions, hardware is required to design again, which takes some works and increases the product cost.
The present invention has been made in order to solve the above problems. It is an object of the invention to provide a composite apparatus and a printer sharing method capable of using an already developed printer board and suppressing an increase in product cost, and to provide a storage medium storing a program for realizing such a method.
In order to achieve the above object, the invention provides a composite apparatus having a plurality of functions including a print function and being connectable to a printer board developed for a general printer and connectable to an external computer, the composite apparatus comprising control means for controlling an entirety of the composite apparatus and print control means for controlling print means which prints image data supplied from the external computer via the printer board or image data supplied from the control means. The composite apparatus comprises selector means provided between the print control means and the printer board for selecting a signal path from the printer board to the print control means and relay means for relaying some of signals to be transferred from the printer board to the print control means, wherein the selector means changes the signal path so that when image data supplied from the printer board via the external computer is printed, predetermined high speed signals output from the printer board are directly received and output to the print control means, and signals other than the predetermined high speed signals output from the printer board are received via the relay means and output to the print control means, and when image data supplied from the control means is printed, the predetermined high speed signals and the signals other than the predetermined high speed signals output from the control means are supplied to the print control means.
Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.